Video signal processing apparatus and method thereof

Abstract

A motion amount at a pixel position to be interpolated of a field of interest is calculated. A difference coefficient between frames is calculated based on video signals of two fields which are adjacent to the field of interest and are separated by one frame. A motion intensity between fields is calculated based on video signals of the field of interest and a field after the field of interest. The motion amount is corrected using a predetermined function. The corrected motion amount is corrected again based on the difference coefficient and motion intensity.

1. A video signal processing apparatus for detecting a motion amount of an object on converting an interlaced-scanning video signal into a progressive-scanning video signal, comprising:
 a motion-amount calculator, configured to calculate the motion amount at a pixel position to be interpolated of a field of interest; 
 a coefficient calculator, configured to calculate a difference coefficient between frames based on video signals of two fields, which are adjacent to the field of interest and are separated by one frame; 
 an intensity calculator, configured to calculate a motion intensity between fields based on video signals of the field of interest and a field after the field of interest; 
 a first corrector, configured to correct the motion amount using a predetermined function; and 
 a second corrector, configured to correct the motion amount corrected by the first corrector, based on the difference coefficient and the motion intensity. 
 
     
     
       2. The apparatus according to  claim 1 , wherein the predetermined function has characteristics that converge the motion amount to a lower limit when the motion amount assumes a value around the lower limit, and converge the motion amount to an upper limit when the motion amount assumes a value around the upper limit. 
     
     
       3. The apparatus according to  claim 1 , wherein the motion-amount calculator comprises:
 an intra-field calculation unit, configured to calculate an intra-field motion amount based on values of two pixels which are located on lines adjacent to a line where the pixel to be interpolated is located, and which are adjacent to the pixel to be interpolated; 
 an inter-field calculation unit, configured to calculate an inter-field motion amount based on an average value of the two pixels or a value of one of the two pixels, and a value of a pixel corresponding to the pixel to be interpolated on a field before the field of interest; and 
 a motion-amount calculation unit, configured to calculate a motion amount at the pixel position to be interpolated based on the intra-field motion amount and the inter-field motion amount. 
 
     
     
       4. The apparatus according to  claim 1 , wherein the coefficient calculator calculates the difference coefficient between the frames based on difference absolute values of values of pixels located at identical positions of predetermined regions having the pixel to be interpolated as a center between the two fields. 
     
     
       5. The apparatus according to  claim 1 , wherein the intensity calculator generates a frame structure of a predetermined size from the field of interest and the field after the field of interest, and calculates an intensity of an artifact generated in the frame structure as the motion intensity. 
     
     
       6. The apparatus according to  claim 1 , further comprising an interpolator configured to calculate, based on the motion amount corrected by the second corrector, a value of the pixel to be interpolated from a video signal of the field of interest and a video signal of a field before the field of interest. 
     
     
       7. A video signal processing method of detecting a motion amount of an object on converting an interlaced-scanning video signal into a progressive-scanning video signal, comprising the steps of:
 calculating the motion amount at a pixel position to be interpolated of a field of interest; 
 calculating a difference coefficient between frames based on video signals of two fields, which are adjacent to the field of interest and are separated by one frame; 
 calculating a motion intensity between fields based on video signals of the field of interest and a field after the field of interest; 
 correcting the motion amount using a predetermined function; and 
 correcting the motion amount corrected in the first correcting step, based on the difference coefficient and the motion intensity. 
 
     
     
       8. A non-transitory computer-readable medium storing a computer-executable program for causing a computer to perform a video signal processing method of detecting a motion amount of an object on converting an interlaced-scanning video signal into a progressive-scanning video signal, comprising the steps of:
 calculating the motion amount at a pixel position to be interpolated of a field of interest; 
 calculating a difference coefficient between frames based on video signals of two fields, which are adjacent to the field of interest and are separated by one frame; 
 calculating a motion intensity between fields based on video signals of the field of interest and a field after the field of interest; 
 correcting the motion amount using a predetermined function; and 
 correcting the motion amount corrected in the first correcting step, based on the difference coefficient and the motion intensity.